For the repair of a bone defect, it is important, in parallel with the installation of a replacement structure, to promote the reconstruction of bone tissue which will gradually colonize or take the place of the bone substitute.
To this end, specific materials, known as bioactive materials, having been developed by the prior art. When they are implanted in the body, these materials are capable of reacting chemically with the biological fluids, the product of the reaction being a hydroxyapatite which promotes the formation of the bone matrix and bone growth.
Such bioactive materials developed by the prior art are, for example, bioactive glasses of soda-lime phospho-silicate type, corresponding to the general formula SiO2—P2O5—CaO—Na2O. An example thereof is the glass sold under the name BIOGLASS®, with a molar composition: 55% SiO2—20% CaO—20% Na2O—5% P2O5 (Hench et al., 1971, J. Biomed. Mater. Res., 2, 117-141; Hench et al., 1973, J. Biomed. Mater. Res., 7, 25-42).
Such glasses are conventionally prepared by “fusion” techniques, providing a heat treatment at very high temperature, in order to obtain the vitreous material. They exhibit in particular the disadvantage of a relatively rapid surface dissolution in the body, of the order of a few hours. Glasses composed solely of phosphorus and calcium oxides have furthermore been developed (Pemberton et al., 1991, Chem. Mater., 3, 195-200). These glasses are prepared solely by fusion and exhibit surface dissolution kinetics which are also very rapid, of only a few hours.